Screening for alcohol misuse offers opportunities for early detection and delivery of developmentally appropriate interventions among adolescent and young adult patients in medical settings. Although screening and brief interventions have shown promise among adolescents and young adults in the Emergency Department (ED), few studies have fully tested promising screening and brief intervention/treatment/referral components, perhaps due to logistical and practical impediments for the adoption in this setting. Therefore, the proposed study will use computerized screening using touch- screen computer tablets with audio (~5,700 patients) and will test developmentally appropriate, tailored intervention strategies in a two-factorial design (3x2). Specifically, 900 patients aged 14-20 in the ED who screen positive for problematic alcohol use (AUDIT score >=2 ages 14-17 and >=3 ages 18-20) in the past 3 months will be randomized to the combinations of three ED-based conditions (computer brief intervention-CBI; intervener delivered brief intervention-IBI ; enhanced usual care-EUC), and two follow-up conditions (adapted motivational enhancement therapy-AMET; enhanced usual care-EUC) that will take place 3 months post-ED. Interventions will be tailored to address individual differences (e.g., alcohol use patterns, stage of change, barriers/benefits of change) across key developmental transitions (e.g., acquiring a driver's license, living independently, etc.) All participants will receive written information regarding community resources; individuals who meet AUD criteria will additionally receive substance use treatment referrals. Stratified random assignment [by gender, age (14-17; 18- 20), and criteria for AUD] will take place at baseline for all ED-based and follow-up conditions. Recognizing that brief interventions are important, but not necessarily sufficient, for change in all adolescents and young adults who misuse alcohol, the primary specific aims of the proposed study will determine the independent effectiveness of immediate on-the-spot ED-based brief intervention conditions, 3-month follow-up brief treatment conditions, and combinations of conditions, for decreasing alcohol use and improving health-related outcomes (including injury, mental health, and other risk behaviors) at 6- and 12-months follow-up. The use of state-of-the-art computer technology for screening and brief interventions has the potential to reach greater numbers of underage drinkers presenting to the ED than is possible with person-delivered screening and brief intervention. Developing methods to efficiently and effectively optimize screening and brief intervention components has wide-ranging and powerful public health implications for modifying risk trajectories to reduce alcohol misuse and to prevent the development of AUD's among underage drinkers.